#include<iostream>
#include<vector>
using namespace std;

int main(){
	int a[6]={9,8,7,6,5,4};  //设定一个数组
	
	vector<int> v={2,0,2,4};  //指定这个数组的内的元素
	cout<<v.capacity()<<endl;
	
	v.push_back(7);
	cout<<v.capacity()<<endl;

	cout<<"begin:->"<<*v.begin()<<endl;
	cout<<"end:->"<<*(v.end()-1)<<endl;

	cout<<"front:"<<v.front()<<endl;
	cout<<"back:"<<v.back()<<endl;
	

	return 0;
}

